1. Field of the Invention
The invention relates to a reverse projection system for imagery, in which an imagery projection system is placed wholly or partially within a substantially closed, translucent geometric viewing surface and by which images are visible to an observer from outside the substantially closed, viewing surface. In particular, the invention relates to a reverse projection system for moving imagery, in which a moving imagery projection system is placed wholly or partially within a translucent balloon or globe.
2. Description of Related Art
Projection systems are currently used to project moving or still images onto geometric, e.g., domed or hemispherical, viewing surfaces. Some examples of these systems and their viewing surfaces are starfield projectors which project stationary or moving images onto the interior surface of planetarium domes or laser projectors which project laser beams forming stationary or moving images onto geometric viewing surfaces or screens. Such systems suffer from several disadvantages. First, the projected images may only be viewed by observers positioned beneath or in front of the viewing surface. Thus the number of observers is limited by the number of viewing positions that may be located before or beneath the viewing surface. This number is usually less than the absolute number of persons capable of observing the viewing surface because observers viewing the surface from extreme angles may experience unacceptable image distortion. Second, the clarity of the observed images may be adversely effected by the physical condition of the viewing surface. For example, warping of the viewing surface and damaged or deteriorating coatings on the viewing surface (e.g., peeling or xe2x80x9cyellowing⇄ paint or flaking plaster) may cause image distortion. Third, with respect to planetariums, the viewing surface must be free from obstructions such as supporting beams or columns. This requirement imposes architectural limitations on the on the size of the viewing surface and the number of observers who may be placed beneath it.
A need has arisen for a reverse projection system for imagery, which permits viewing of stationary or moving images on a substantially closed, viewing surface. The system may be used to generate images for educational or entertainment purposes, or the like. In particular, the viewing surface may comprise a rigid viewing surface, such as a self-supporting globe, sphere, or other geometric shape, manufactured from a translucent plastic or glass or the like. Alternatively, the viewing surface may comprise a non-rigid or semi-rigid viewing surface, such as an inflated balloon having a globe, sphere, or other geometric shape, manufactured from a translucent plastic or fabric, or the like. Such balloon viewing surfaces may be inflated with a gas or a combination of gasses, e.g., helium or hydrogen, or with heated air, or with the like.
By allowing the images to be observed from the exterior of the viewing surface, the number of observers capable of watching the moving or stationary images can be greatly increased. Further the images may be shown at essentially any location at which observers may gather. However, the projection systems of the present invention may be especially well suited to displaying stationary or moving images to observers in arenas, stadiums, amphitheaters, ballparks, or other venues having tiered seating arrangements.
In an embodiment, a projection and display system for reverse projection of imagery may comprise an imagery projection system having a lens barrel for projecting at least one image. The imagery projection system extends into a substantially closed, geometric viewing surface, such that the lens barrel is disposed at a predetermined distance from and at a predetermined orientation relative to an interior surface of the geometric viewing surface. The at least one image is projected onto an interior surface of the geometric viewing surface. The image may be defined in vector coordinates or in raster coordinates.
Various configurations for the viewing surface are possible. The viewing surface may be rigid, e.g., a globe, semi-rigid, or non-rigid, e.g., a balloon. Moreover, the viewing surface may be integral or may be formed in segments which form a continuous or discontinuous viewing surface. Nevertheless, each configuration must be at least partially translucent or at least partially transparent, or both, so that the images projected on the interior of the viewing surface may be seen by observers on the exterior of the viewing surface.
The imagery projection system may be a moving imagery projection system comprising a source of an intense light beam; a scanning deflector module for deflecting the light beam to the coordinates in a pair of Cartesian axes at an exit angle of deflection of the light beam; and a wide angle lens array for increasing the exit angle of deflection by a predetermined factor and projecting the image on the viewing surface. For example, an OMNISCAN(trademark) laser imagery projection system, available from Audio Visual Imagineering, Inc., of Orlando, Fla., may be adapted to project suitable images. The deflector module may be a vector scanning deflector module or a raster scanning deflector module. The generated light beam may be a laser beam.
In another embodiment of the invention, a mobile, reverse projection system comprises an electronic control unit (ECU) and a projection head mounted on a balloon, wherein the projection head and the ECU are joined by an umbilical cord. The umbilical cord comprises at least one power transfer cable to supply power and data to a plurality of deflectors in the projection head and at least one fiber optic cable to transfer light from a light source in the ECU to the projection head for projection within the balloon. The umbilical cord may be sheathed with a material selected from the group consisting of a metal, a polymer, a composite material including glass fibers, or combinations thereof. Further, the umbilical cord may have a strengthened core of a material selected from a group consisting of a metal, a polymer, a composite material including glass fibers, or combinations thereof.
The system also may comprise a first coupler which joins the umbilical cord to the ECU. The projection head includes a second coupler which joins the umbilical cord to the deflectors in the projection head, wherein a second junction pivotally connects the umbilical cord to the second coupler in the projection head. The first coupler also may include a first junction which connects the umbilical cord to the first coupler. Moreover, the first junction pivotally may connect the umbilical cord to the first coupler.
As noted above, the viewing surface may be translucent or may comprises at least one transparent portion, such that at least a portion of the at least one image projected within the viewing surface escapes through the at least one transparent portion of the viewing surface. Further, if the viewing surface is a balloon, the balloon may be partially transparent, such that at least a portion of the light projected with the balloon escapes from within the balloon.
The ECU may have a plurality of wheels. Alternatively, the ECU may be carried on an aircraft, e.g., an airship or a helicopter, or a watercraft, e.g., a boat, ship, or barge. Moreover, if the viewing surface is a balloon, the balloon and projection head may suspended beneath an overhead mounted ECU.
In still another embodiment, a reverse projection system for imagery may include an imagery projection system and a substantially closed, translucent geometric viewing surface, wherein at least a projector or lens array of the imagery projection system is partially enclosed by the translucent viewing surface. The viewing surface may be sealed around the imagery projection system by a collar at its point of insertion into the viewing surface.
In yet another embodiment, a reverse projection system for imagery may include an imagery projection system and a translucent balloon or globe, wherein at least a projector or lens array of the imagery projection system may be wholly or partially enclosed by the translucent balloon or globe. If at least the projector or lens array of the imagery projection system is partially enclosed by the translucent balloon, the balloon or globe may sealed around the imagery projection system by a collar, at its point of insertion into the balloon. The balloon may be inflated with compressed or heated air or another fluid or gas, such as helium or hydrogen, and the seal around a partially inserted imagery projection system (e.g., around a projection head from which light (or laser) beams for generating the images emanate) may be substantially fluid-or gas-tight. Alternatively, the viewing surface may be a rigid viewing surface such as a globe surrounding a projection head from which light (or laser) beams for generating the images emanate.
In a further embodiment of the system, the components of a laser projection system may be separated from each other and light may be transferred between the components by means of fiber optic cables. Thus, the laser or other source of an intense light beam may be located remotely from the other components of the projection system. A projection head may be located remotely from the light beam source and may comprise a lens array for focusing the image onto the interior surface of the viewing surface and a scanning deflector module, such as a vector or raster scanning deflector module for deflecting the light beam through the lens array in a pair of Cartesian axes. The light beam source and ancillary, system components, such as power supplies and computers for generating graphic imagery, may be carried in the ECU. The components located in the ECU may be connected to the projection head by means of a fiber optic umbilical cord. Thus, for example, the projection head may be mounted in an inflated balloon hovering aloft. Such a hovering projector head may receive electric and optical input via a fiber optic umbilical cord from an ECU on the ground. Moreover, the ECU may be mobile or even self-propelled, so that it may follow remotely below the hovering projection head and the balloon.
Alternatively, the balloon or globe may be suspended from a trapeze or guiding arm, by which it may be moved through a confined space such as an arena, a stadium, or a tent, or the like. Similarly, the balloon or globe may be suspended from a helicopter, a blimp, or other rigid or non-rigid aircraft, including another balloon.
Other objects, features and advantages of this invention will be apparent from the enclosed drawings and the following detailed description of preferred embodiments.